Control manners of conventional display panels are that a power supply circuit directly outputs a power supply voltage to an OLED (Organic Light-Emitting Diode) display panel. For the OLED display panel, the power supply voltage outputted by the power supply circuit can cause great impact on a Gamma voltage, however, an adjusted Gamma voltage has already been burned in a driver IC (integrated Circuit) before shipment of the OLED display panel, under normal circumstances, the power supply circuit will be placed on a motherboard, the power supply voltage is transmitted through a FPC (Flexible Printed Circuit) to reach the OLED display panel, there will be some voltage drop loss during the transmission. And layout of peripheral circuits of the power supply circuit will also have great impact on the power supply voltage outputted by the power supply circuit, thus it is impossible to guarantee that a value of the power supply voltage inputted into the OLED display panel when burning the Gamma voltage is the same as a value of the power supply voltage outputted to the OLED display panel from the motherboard, as a result, it is likely to affect the display effect of the OLED display panel. In addition, during actual displaying of the OLED display panel, different loads will also affect an actual output of the power supply voltage and cause an IR drop problem, which will also have great impact on the display effect of the OLED display panel.